Quote:
Originally Posted by jiang  
Dear Mike,
Thank you very much for your further explanation. In my dictionary it reads:
the fact of not being affected by adisease or harmed by something unpleasant.
But the first meaning of your explanation is different from that in my dictionay. Could you please kindly further explain it?
Looking forward to hearing from you.
Thank you in advance.
Jiang |
There are three main ways to acquire immunity to an infectious disease:
1. borrow immunity from one's mother (passive immunity of newborns)
2. develop immunity after having a disease
3. develp immunity after a vaccination (simulates having the disease)
Your dictionary means that once one is immune, one cannot be infected. One way to develop that immunity to have a disease and recover from it. Then you can't get it again (at least for a while).